Healing by Primary and Secondary Intention
Clinicians use the terms primary intention and secondary intention to describe the two basic methods of wound healing. In healing by primary intention, the edges of a wound in which there is no tissue loss are placed and stabilized in essentially the same anatomic position they held before injury and are allowed to heal. Wound repair then occurs with minimal scar tissue, because the tissues would not “perceive” that an injury had occurred. Strictly speaking, healing by primary intention is only a theoretic ideal, impossible to attain clinically; however, toe term is generally used to designate wounds in which the edges are closely reapproxiraated. This method of wound repair lessens the amount of Teepithelialization, collagen deposition, connacnon, and remodeling necessary during healing. Therefore healing occurs moreraptdly, with
a lower risk of infection and with less scar formation than in wounds allowed to heal by secondary intention. Examples of wounds. that heal by primary intention include well-repaired lacerations or incisions, well-reduced bone fractures; and anatomic nerve reanastomoses of recently
severed nerves. In contrast, healing by secondary intention implies that a gap is left between the edges of. an incision or laceration or between bone or nerve ends after repair, or it implies that tissue loss has occurred in a
wound that prevents close approximation of wound edges. These situations require a larg.e amount of epithelial migration, collagen deposition, contraction, and remodeling during healing. Healing is slower’ and produces more scar tissue than is the case with healing by primary intention. Examples of wounds allowed to heal by secondary intention include extraction sockets, poorly reduced fractures, deep ulcers, and large axculsive injuries of any soft tissue.
Some surgeons use the term tertiary intention to refer to the healing of wounds through the use of tissue grafts in large wounds healing by secondary intention.